filter: more consistent labeling of rejections

While we're at it, reject non-plain-text top-level messages,
too.  They probably do not exist in practice, but we cannot
afford to scrub given policies implemented by overzealous
mail providers.

While we're at it, update the comment for strip_multipart.

diff --git a/lib/PublicInbox/Filter.pm b/lib/PublicInbox/Filter.pm
index 6f28e013c44b23072e552fca0c9d9e9643ea6e45..01052d02e3a6de06a07cd65a76988874fee5c3d4 100644 (file)
--- a/lib/PublicInbox/Filter.pm
+++ b/lib/PublicInbox/Filter.pm
@@ -13,6 +13,7 @@ use Email::Filter;
 use IPC::Run;
 our $VERSION = '0.0.1';
 use constant NO_HTML => '*** We only accept plain-text email, no HTML ***';
+use constant TEXT_ONLY => '*** We only accept plain-text email ***';
 
 # start with the same defaults as mailman
 our $BAD_EXT = qr/\.(exe|bat|cmd|com|pif|scr|vbs|cpl|zip)\s*\z/i;
@@ -49,6 +50,7 @@ sub run {
        } elsif ($content_type =~ m!\bmultipart/!i) {
                return strip_multipart($mime, $content_type, $filter);
        } else {
+               $filter->reject(TEXT_ONLY) if $filter;
                replace_body($mime, "$content_type message scrubbed");
                return 0;
        }
@@ -108,10 +110,7 @@ sub dump_html {
        }
 }
 
-# this is to correct user errors and not expected to cover all corner cases
-# if users don't want to hit this, they should be sending text/plain messages
-# unfortunately, too many people send HTML mail and we'll attempt to convert
-# it to something safer, smaller and harder-to-spy-on-users-with.
+# this is to correct old archives during import.
 sub strip_multipart {
        my ($mime, $content_type, $filter) = @_;
 
@@ -152,7 +151,7 @@ sub strip_multipart {
                        if (recheck_type_ok($part)) {
                                push @keep, $part;
                        } elsif ($filter) {
-                               $filter->reject('no attachments')
+                               $filter->reject(TEXT_ONLY);
                        } else {
                                $rejected++;
                        }
@@ -164,7 +163,7 @@ sub strip_multipart {
                                push @keep, $part;
                        }
                } else {
-                       $filter->reject('no attachments') if $filter;
+                       $filter->reject(TEXT_ONLY) if $filter;
                        # reject everything else, including non-PGP signatures
                        $rejected++;
                }